
%0 Journal Article
%A Lovisolo, Claudio 
%A Hartung, Wolfram 
%A Schubert, Andrea 
%T Whole-plant hydraulic conductance and root-to-shoot flow of abscisic acid are independently affected by water stress in grapevines
%J Functional Plant Biology
%D 2002/11/25
%V 29
%N 11
%P 1349-1356
%K ABA, abscisic acid, cavitation, embolism, hydraulic conductivity, root-to-shoot signal, split-root, stomatal conductance, Vitis vinifera L., water stress.
%R https://doi.org/10.1071/FP02079
%U https://www.publish.csiro.au/paper/FP02079 
%X In order to investigate whether plant hydraulic conductance (gplant) is reduced under drought conditions via an ABA-related mechanism, a water-stress experiment was carried out using split-rooted grapevines. In addition, inversion of shoot growth orientation was imposed to reduce gplant independently of soil water availability, and thus of the putative ABA root-generated stress message. As expected, water stress imposed on split-roots affected ABA accumulation. ABA drought-stress message negatively affected stomatal conductance (gs) and transpiration (E), but modified neither leaf or stem water potentials (&#936;leaf and &#936;stem, respectively), nor gplant. When gplant was reduced in split-rooted, shoot-inverted (s-r/s-i) grapevines, &#936;leaf and &#936;stem decreased, without changes in ABA accumulation, gs and E. The ABA drought-stress message did not modify gplant, nor did gplant (impaired by shoot-growth inversion) decrease ABA delivery to the leaves. However, leaf growth was depressed in s-r/s-i grapevines. The fact that no interaction between ABA stress messages (caused by split-root technique) and hydraulic constraints to sap flow (caused by shoot inversion) was necessary to impair leaf growth suggests that the targets of ABA and hydraulic-limitation effects on leaf expansion are not the same. 
